Field of Invention
The instant disclosure relates to a catalyst structure for electrolysis of water and a method of forming the same. More particularly, the present disclosure relates to a catalyst structure including ferric oxide support and cobalt-containing compound catalyst and a method of forming the same.
Description of Related Art
Electrolysis of water is an eco-friendly method for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). That is, water can be converted into hydrogen and oxygen by electric potential. Compared with hydrogen obtained by pyrolysis or steam reforming in traditional industry, the hydrogen generated by electrolysis having higher purity is unnecessary to be further purified and can be used directly. The volume and cost of apparatus for electrolysis are less than traditional industry. Moreover, during electrolysis of water, environmentally harmful by-product may not be produced and the electrolytic method is more eco-friendly thereby.
The hydrogen obtained by electrolysis is versatile. For example, it can be used as fuel of hydrogen fuel cell or thermal power generation. The heating value of hydrogen is 141.8 MJkg−1 which is 2.6 times larger than natural gas, 3 times larger than gasoline and 3.93-9.45 times larger than coal. The combustion product is only water and environmentally harmful by-product may not be generated. Therefore, use of hydrogen energy achieves not only the goal of electric storage but also the fulfillment of eco-friendly concepts. Hydrogen energy has unlimited potential at the present time. Further, the oxygen obtained by electrolysis of water has medical uses and can be used in oxyacetylene welding or iron and steel smelting. The applicability of oxygen is diverse. Therefore, electrolysis of water is a promising method for generating hydrogen and oxygen.
However, the most difficult thing in electrolysis of water is too much energy consumption which keeps up the cost of electrolysis. Accordingly, how to reduce the energy consumption to keep the cost down is popular research topic at the present time. One method to reduce the energy consumption is coating catalysts over electrode to reduce the electrical potential required to be overcome during electrolysis. The past literatures indicated that iron-containing, cobalt-containing and nickel-containing compound catalysts can reduce the electrical potential required to overcome in electrolysis. However, these catalysts are magnetic, such that these catalysts easily cluster together, as a result, the phenomenon is called cluster effect. The cluster effect makes the reaction area of catalysts smaller and the efficiency of catalysts worse. Moreover, the past literatures also use nobel metals. Pt or Ir, as catalyst for electrolysis of water. The nobel metals have high efficiency but high cost as well. In view of the above problems, there is need to provide a new catalyst structure and a method of forming the same.